mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-12-18 06:16:36 +00:00
111 lines
3.9 KiB
XML
111 lines
3.9 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
|
|
<!ENTITY % local.common.attrib "xmlns:xi CDATA #FIXED 'http://www.w3.org/2003/XInclude'">
|
|
]>
|
|
<refentry id="ges-architecture" revision="25 mar 2009">
|
|
<refmeta>
|
|
<refentrytitle>Overview and architecture</refentrytitle>
|
|
|
|
<manvolnum>1</manvolnum>
|
|
|
|
<refmiscinfo>GStreamer Editing Services</refmiscinfo>
|
|
</refmeta>
|
|
|
|
<!-- <refnamediv> -->
|
|
|
|
<!-- <refname>Overview</refname> -->
|
|
|
|
<!-- <refpurpose> -->
|
|
|
|
<!-- Goals of the GStreamer Editing Services. -->
|
|
|
|
<!-- </refpurpose> -->
|
|
|
|
<!-- </refnamediv> -->
|
|
|
|
<refsect1>
|
|
<title>Goals of GStreamer Editing Services</title>
|
|
|
|
<para>The GStreamer multimedia framework and the accompanying GNonLin set
|
|
of plugins for non-linear editing offer all the building blocks for:
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>Decoding and encoding to a wide variety of formats, through
|
|
all the available GStreamer plugins.</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Easily choosing segments of streams and arranging them through
|
|
time through the GNonLin set of plugins.</para>
|
|
</listitem>
|
|
</itemizedlist></para>
|
|
|
|
<para>But all those building blocks only offer stream-level access, which
|
|
results in developers who want to write non-linear editors to write a
|
|
consequent amount of code to get to the level of <emphasis>non-linear
|
|
editing</emphasis> notions which are closer and more meaningful for the
|
|
end-user (and therefore the application).</para>
|
|
|
|
<para>The GStreamer Editing Services <remark>(hereafter GES)</remark> aims
|
|
to fill the gap between GStreamer/GNonLin and the application developer by
|
|
offering a series of classes to simplify the creation of many kind of
|
|
editing-related applications.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Architecture</title>
|
|
|
|
<refsect2>
|
|
<title>Timeline and TimelinePipeline</title>
|
|
|
|
<para>The most top-level object encapsulating every other object is the
|
|
<link linkend="GESTimeline">GESTimeline</link>. It is the central object
|
|
for any editing project.</para>
|
|
|
|
<para>The <classname>GESTimeline</classname> is a
|
|
<classname>GstElement</classname>. It can therefore be used in any
|
|
GStreamer pipeline like any other object.</para>
|
|
</refsect2>
|
|
|
|
|
|
<refsect2>
|
|
<title>Tracks and Layers</title>
|
|
|
|
<para>The GESTimeline can contain two types of objects (seen in <xref
|
|
linkend="layer_tracks_diagram" />): <itemizedlist>
|
|
<listitem>
|
|
<para>Layers - Corresponds to the user-visible arrangement of clips,
|
|
and what you primarily interact with as an application developer.
|
|
A minimalistic timeline would only have one layer,
|
|
but a more complex editing application could use as many as needed.
|
|
</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Tracks - Corresponds to the output streams in GStreamer.
|
|
A typical GESTimeline, aimed at a video editing application, would
|
|
have an audio track and a video track.
|
|
A GESTimeline for an audio editing application would only require
|
|
an audio track. Multiple layers can be related to each track.</para>
|
|
</listitem>
|
|
</itemizedlist></para>
|
|
|
|
<figure float="0" id="layer_tracks_diagram">
|
|
<title>Layers and Tracks</title>
|
|
|
|
<mediaobject>
|
|
<imageobject>
|
|
<imagedata fileref="layer_track_overview.png" scale="75" />
|
|
</imageobject>
|
|
</mediaobject>
|
|
</figure>
|
|
|
|
<para>In order to reduce even more the amount of GStreamer interaction
|
|
the application developer has to deal with, a convenience GstPipeline
|
|
has been made available specifically for Timelines : <link
|
|
linkend="GESPipeline">GESPipeline</link>.</para>
|
|
</refsect2>
|
|
|
|
</refsect1>
|
|
</refentry>
|